Answer:
The other two dimensions are either (x+9) or (x-7). other two dimensions are either 21 inches or 7 inches.
Explanation:
The volume is defined by the function.

The width is (x+3).
Using synthetic or long division method divide
by (x+3).



The volume of cuboid is

Therefore other two dimensions are either (x+9) or (x-7).
If the width is 15 inches, then


The other two dimensions are


Therefore other two dimensions are either (x+9) or (x-7). other two dimensions are either 21 inches or 7 inches.